Anaphylaxis provoked by ingestion of hydrolyzed fish collagen probably induced by epicutaneous sensitization

Large amount of products derived from fish collagen, such as gelatin, hydrolyzed fish collagen and atelocollagen, are consumed as dietary supplement, sweets, cosmetics and moisturizers today. We report a patient with atopic dermatitis who experienced episodes of anaphylaxis after ingestion of dietary supplement or gummy candy, both of which contained the hydrolyzed fish collagen sold under a trade name “fish collagen peptide” even though it contained high molecular weight proteins. The patient started applying a moisturizer containing fish atelocollagen on her face 15months before the first episode of anaphylaxis. We speculate that long term application of themoisturizer on impaired skin surface induced epicutaneous sensitization of fish collagen. In May 2013, a 30-year old woman with a history of atopic dermatitis was referred for evaluation after episodes of anaphylaxis, which occurred twice after ingestion of yogurt with a dietary supplement, AC, sold by company A, that was made from hydrolyzed fish collagen, “fish collagen peptide”. Every episode occurred within several minutes after consuming 1 package of the dietary supplement with development of lip swelling, itching of eyes, throat and genitalia, and airway constriction. Since June 2009, the patient had started eating yogurt with the dietary supplement, AC. Total IgE level was 1260 IU/ml. In May 2014, the patient returned to the clinic due to anaphylactic reaction after ingesting gummy candies. She noticed that anaphylaxis was provoked just by one particular fish collagen-containing gummy candy sold by company A, but never by several different gummy products without fish collagen. Because both AC and this gummy candy are produced by the same company, we assumed that these products contain the allergen. Skin prick test was positive for the supplement, AC (100 mg/ml water) and the hydrolyzed fish collagen, “fish collagen peptide”, supplied by company A (100 mg/ml water), an ingredient of the gummy candy (Table 1). In further inquiry, the patient disclosed that, in February 2012 when facial dermatitis worsened, she had started applying a moisturizer sold by company E containing fish atelocollagen, which is fish triple helix collagen of molecular weight of 350 kDa, composed of three alpha chains with molecular weights of approximately 110e120 kDa. Skin prick test responses were also positive for the moisturizer, fish atelocollagen supplied by company E and fish gelatin supplied by company D, but negative for several samples of gelatin derived from porcine skin or bovine bone (Table 1). The